Refrigerating apparatus



July 11, 1950 L. A. PHVILIPP 2,514,792

REF'RIGERATING APPARATUS Filed Sept. 26', 1947 INVENTOR. LnweE/vcs fl- PHIL/PP H TTOBNE Y Patented July 11, 1950 I nnrmonaamc APPARATUS Lawrence A. Philipp, Detroit, Mich., assignor to Nash-Kelvinator Corporation, Detroit, Mich., a corporation of Maryland Application September 26, 1947, Serial No. 776,186

I 5 Claims. ((162-116) This invention relates generally to refrigerating apparatus and more particularly to refrigerating systems for household type refrigerators.

. One of the objects of my invention is to provide an improved multl-temperature refrigerating system of increased operating efficiency.

Another object of my invention is to provide an improved arrangement and association of units of a multi-temperature refrigerating system to reduce the work of the compressor with corresponding general increase in the efliciency of the system.

Another object of the invention is to increase the efficiency of multi-temperature refrigerating systems inexpensively Further objects and advantages of the present invention will be apparent from the following description reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

The figure of the drawing is a side view with parts broken away and parts shown in section of a refrigerator cabinet combined with a diagrammatic view of a refrigerating system embodying features of the present invention.

Referring to the drawing, there is shown a household type refrigerator cabinet, designated generally by the numeral 20. The cabinet 20 may comprise, in general, an outer sheet metal casing 22 and two individual sheet metal liners 24 and 25 respectively. Interposed between the outer casing 22 and the liners 24 and 25 is heat insulation 26. This insulation 26 may be of any suitable type, such as cork, or a fibrous material having good heat insulating properties. The liner 24 forms a frozen food compartment .34, and the liner 25 forms a food storage compartment 38. A door 40 is" provided for closing an access opening in the front of the cabinet to the frozen food compartment 34, and a similar door 42 may be provided for closing an access opening to the food storage compartment 38. A plurality of vertically spaced shelves 44 may be provided in the food storage compartment 38 and may be imperforate members made of transparent glass or other suitable material.

The refrigerating system for cooling compartments 34 and 38 comprises, in general, a relatively low temperature refrigerant evaporator 46, a relatively high temperature refrigerant evaporator 41, a refrigerant distributing header or accumulator 48 and a refrigerant condensing element 50. The condensing element 58 comprises, in general, a motor-compressor unit 52 and a condenser 54.

5 As shown, the refrigerant evaporators 46 and 41 are preferably conduits or coils of. serpentine form, respectively arranged in good heat transfer relationship with the outer surfaces of the liners 24 and 25. The refrigerant distributing header 48 may be mounted on the cabinet rear wall and be imbedded in the insulation, above the relatively high temperature evaporator 41 and below the relatively low temperature evaporator 46.

Liquid refrigerant is supplied to the header 48 from the condenser 54 through a control or capillary tube 56; the header being normally maintained partially filled with liquid refrigerant as illustrated. Opposite ends of the relatively high temperature evaporator coil 41 are connected in communication with the interior of the header 48 below the level of the liquid refrigerant therein providing a liquid refrigerant circulating system in which the evaporator 41 is maintained substantially flooded. As shown, the inlet end, as at 58, of the evaporator 41 is connected to the header 48 below the outlet end, as at 59, of the evaporator. Liquid refrigerant, together with some gaseous refrigerant is supplied to the relatively low temperature evaporator 46 through a flow restricting or capillary tube 68 which maintains a pressure differential between the evaporators. In order to control flow of liquid refrigerant from the header 43 to the'evaporator 46, I arrange to skim the refrigerant from its surface level in header 48 by arranging the inlet end, as at 62, of the capillary tube 60 directed downwardly and terminating above the outlet end 58 of evaporator 41 but below the top of header 48. Refrigerant expands in the evaporator coil 46 and the initial charge of refrigerant is such that very little, if any, liquid passes into anaccumulator 64 which may be provided at the discharge end of the evaporator. Gaseous refrigerant is withdrawn from the accumulator 64 by the motorcompressor unit through a return conduit 66 to be again compressed and delivered to the conden:er 54. Preferably, a-portion of the capillary tube 56 is arranged, as shown, in good heat transfer relation with the return conduit 66 to cool the gaseous refrigerant returning to the motorcompressor unit. a 1

The motor-compressor unit comprises, in general, a compressor air-electric, compressor driving motor (not shown) and a sealed casing II. The compressor; 'Hlhas a pair of piston cylinders l2, 14; the cylinder 12 having a larger cubic displacement than the cylinder 14. The sealed casing H encloses the compressor T0 and the compressor driving motor providing a fluid the casing H, the return conduit 66 is connected to an inlet 82 of the compressor cylinder I2. This cylinder 12 is provided with an outlet 84 discharging compressed refrigerant directly into the casing chamber 18. The other or smaller piston cylinder 14 has an intake 88 in the casing chamber 18 and has an outlet to which the inlet end of the condenser 54 is connected. A second refrigerant return conduit 88 is provided and leads from the header 48, above the liquid level therein, to the casing chamber 18 for the return of the relatively high pressure gaseous refrigerant to the compressor. The high pressure refrigerant discharging into the casing chamber 18 from the return conduit 88 increases the pressure of the refrigerant in the chamber 18 above the pressure of the refrigerant being discharged from the larger cylinder 12 into the chamber. As a result less work is needed to raise the pressure of the refrigerant in chamber 18 to the desired pressure and this may be accomplished by the relatively smaller piston. The gaseous refrigerant in chamber 18 is taken into the smaller piston cylinder 14 through the intake 86 and is compressed and delivered to the condenser 54.

From the foregoing description, it will be noted that I have provided an improved arrangement and association of refrigerating apparatus units to increase the efllciency of multi-temperature refrigerating systems. This increased efliciency is effected by the provision of individual suction return conduits leading respectively from the evaporators to a common refrigerant condenser. It will be further noted that in my system, the evaporators are supplied in parallel from a common header and that refrigerant is taken from the surface of the refrigerant in said header into the relatively low temperature evaporator.

Although only a preferred form of the invention has been illustrated, and that form described in detail, it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. Refrigerating apparatus comprising. a refrigerant distributing header, a refrigerant condenser communicating .with and supplying liquid refrigerant to said header below the refrigerant liquid level therein, a refrigerant compressor having an inlet communicating with said header above the level of the liquid refrigerant therein and having an outlet communicating with said condenser, a relatively low temperature refrigerant evaporator having an inlet communicating with said header substantially at the refrigerant liquid level therein and having an accumulator, a return conduit directly connecting said accumulator with said compressor, and a relatively high temperature refrigerant evaporator having an inlet and an outlet communicating with said header with said last-named inlet being below the liquid level of the refrigerant in said header.

2. Refrigerating apparatus comprising, a refrigerant distributing header normally partially filled with liquid refrigerant, a relatively high temperature refrigerant evaporator having an inlet and an outlet communicating with said header below the level of the refrigerant therein, a refrigerant compressor having an outlet and having a pair of inlets, a refrigerant condenser in communication with said compressor outlet, a refrigerant supply tube connecting said condenser and said header, a relatively low temperature refrigerant evaporator, a flow restricting tube connecting said relatively low temperature refrigerant evaporator to said header substantially at the refrigerant liquid level therein, a refrigerant return conduit connecting said relatively low temperature evaporator to said compressor, and a second refrigerant return conduit connecting said header above the refrigerant level therein to said compressor.

3. Refrigerating apparatus comprising, a refrigerant distributing header, a refrigerant condenser communicating with and supplying liquid refrigerant to said header, a refrigerant compressor having an outlet communicating with said condenser, a sealed' casing enclosing said compressor communicating with said header above the liquid level of refrigerant therein, a relatively low-temperature refrigerant evaporator having an outlet communicating with said compressor, a flow restricting tube connecting said header substantially at the level of the liquid refrigerant therein to said relatively low temperature evaporator, and a relatively high temperature refrigerant evaporator having an inlet and an outlet communicating with said header below the level of the liquid refrigerant therein.

4. Refrigerating apparatus comprising, a refrigerant distributing header normally partially filled with refrigerant, a refrigerant condenser communicating with and supplying liquid refrigerant to said header, a relatively high temperature refrigerant evaporator below the level of the liquid refrigerant in said header, a relatively low temperature evaporator having a refrigerant accumu ator, a flow restricting tube connecting the inlet of said relatively low temperature evaporator to said header substantially at the surface of the refrigerant therein, a refrigerant compressor having a relatively small capacity piston cylinder communicating with said refrigerant condenser and having a relatively large capacity piston cylinder communicating with said accumulator, and a sealed casing enclosing said compressor communicating with said header above the level of the liquid refrigerant therein.

5. Refrigerating apparatus comprising. a refrigerant distributing header normally partially filled with liquid refrigerant, a refrigerant condenser communicating with and delivering liquid refrigerant to said header, a relatively high temperature refrigerant evaporator having an inlet and an outlet in communication with said header, a relatively low temperature evaporator having a refrigerant inlet and a refrigerant outlet, a flow restricting passage connecting said header communicatively to the inlet of said relatively low temperature evaporator, a refrigerant compressor having a relatively small capacity piston cylinder communicating with said refrigerant condenser and having a relatively large capacity piston cylinder communicating with the outlet of said relatively low temperature evaporator, and a sealed casing enclosing said compressor and communicating with said header above the level of the liquid refrigerant therein.

. LAWRENCE A. PHILIPP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,048,218 Philipp July 21, 1936 2,133,949 Buchanan Oct. 25, 1938 

